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Solution and Solid Phase Synthesis of Unusual a-Amino Acids From

Solution and Solid Phase Synthesis of Unusual a-Amino Acids From

Solution and Solid Phase Synthesis of Unusual a-Amino Acids From

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acetate:MeOH over 5 min then to 60:40 over 100 min) indicated a rhreo:e~hro ratio <strong>of</strong><br />

99: 1 with 99% ee (threo-L-2.W. 73.1 min. threo-D-2.60: 77.8 min, erythro-L-2-60: 7 1 -6<br />

min, erythro-D-2.60: 76.3 min).<br />

mp 220-225°C (dec); TLC (1 : 1 : 1 : 1. EtOAc:nBuOH:MeOH:H20) Rf = 0.56; 'H NMR<br />

@20. 250 MHz) 6 3.5 1 (s, 1 H, CECH), 1.65- 1.53 (rn, 2H, J = 7.7Hz. CH3C&), 1 .O9 (s,<br />

3H, B-CH3), 0.79 (t, 3H. I = 7.7&, CH3CH2); I3c NMR (D@, 63 MHz) 8 175.1 (CO2H),<br />

72.6 (p-Q, 64.5 (a-CH). 34.7 (@-CH&Hz), 24.1 @-CH3), 10.0 (p-cH3CH2); ESI-MS (M<br />

+FI+) 147.93.

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